Catapult for gliders



Feb. 23, 1932. v. A. STEVENS 1,846,157

` cATAiDULT FOR GLIDEHS Filed June 2B, 1930 v 2 sheets-sheet 1 23 FIG. 21 7 2 .-7 7

26 ATTORNEYS.

Feb. 23, 1932. V` STEVENS 1,846,157

CATAPULT FOR GLIDERS Filed June 28, 1930 2 Sheets-Shet 2 FIG. 6.

BMmM/M ATTORNEYS.,

Patented Feb. 23, 1932 UNITED `STATES PATENT iol-FICE CATALPULT FOR GLIDEBS Application illed .Tune 28, 1930. Serial No. 464,619.

The present invention relates to launching devices for gliders, sail planes, model planes and similar motorless aircraft and the primary object of the invention is to provide a device of this character whereby a single attendant may effectively launch the aircraft.

A further object of the invention is to provide a launching device for gliders which will permit launching of the glider by the pilot while seated in the glider and without the usual ground crew for launching of the O'lider.

b A further object resides in the novel arrangement whereby the glider is launched without a sudden shock during initial launching movement.

A further object resides in the novel arrangement of the launching means whereby the aircraft will be projected with considerable propelling force.

A still further object resides in the novel towing means for the glider and the manner in which the glider is automatically released from the towing means.

A still further and important object of the invention is to provide a catapult or launchino device for gliders which is readily porta le in that the same is of knockdown construction thus permitting ready movement from place to place and positioned for best results according to prevailing winds or air currents.

Other objects and advantages of the invention will be apparent during the course of the following detailed description, taken in connection with the accompan ing drawings forming a part of this specification and in which drawings:

Figure 1 is a top plan view of the device and showing the parts in a launching condition.

Figures 2 and 3 are enlarged fragmentary sections on the respect-ive lines in Figure l showing the manner in which the towing block is mounted in the launching track.

Figure 4 is a horizontal section on the line 4-4 of Figure 2 and showing the arrangement for retarding initial movement of the towing block when released.

Figure 5 is a fragmentary View part in side elevation and part in section of the retracting or tensioning means for the propelling means.

Figure 6 is a transverse section on line 6--6 of Figure 1.

Figure 7 is a transverse section on the line 7-7 of Figure 8.

Figure 8 is a fragmentary longitudinal section thru the track showing the arrangement for freeing the shock cord and glider coupling rings from the towing block.

Figure 9 is an enlarged fragmentary section on the line 9-9 of Figure 1 showing the lnanner of mounting the spring bow at the forward end of the track.

In the drawings, and wherein similar reference characters designate corresponding parts thruout the several views, the letter A designates a launching track providing a runway for a glider or any type of motorless aircraft diagrammatically shown at B, C launching means for launching the glider B, D retracting or tensioning means for the launching means C, and E release means for the launching means C. j

Referring first tothe specific construction of t-he launching track A, the same is preferably of sectional construction to permit transportation of the device and in actual practice the track is of one hundred or more feet in length. The track A is of special formation embodying a channel-shaped lower portion 4 'being open at its upper side and providing a bottom wall 5 and parallel upstanding side walls 6 which may have outturned flanges along their upper edges. Secured along the upper edge of each side wall 6 is an angle or L-shaped guide rail 7 the horizontal iange portions of which project over and partially close the upper side of the channel-shaped lower track portion and have their adjacent edges slightly spaced apart to provide a guide slot 8 extending thruout the length of the track A midway between the walls 6. These angle-shaped guide rails 7 provide a runway along which the glider is moved and in which the glider skid has sliding movement during the launching operation. The inwardly overhanging portions of the guide rails 7 partially close the upper side of the tiack channel and provide a slide way 9 being closed at all sides with the eX- ception of the longitudinal guide slot 8 opening into the top of the slide way 9.

The track sections or portions may be held in longitudinal alignment by means of suitable coupling plates l0, and the plates 10 serving to couple the two central track sections are preferably each provided with a laterally projecting brace 'arm 11. nected in eyes at the other ends of the brace rods 1l are suitable truss rods 12 which eX-V tend from the brace arms to opposite ends of the track and are attached to suitableV brackets 13 carried by the channel side walls 6. These truss rods 12 serve to stiffen the.

track and are preferably provided withV suitable turn-buckles 14. Secured to the under side of the track and preferably at the meeting ends of the track sections are transversely disposed supports 15 which aside from yslightly elevating the track serve to prevent side-A wise tilting of the track.

Referring now to the launching or propelling means C, the same includes a cross spring bow 16 secured transversely of` the forward end of the track A upon a suitable cro-ss head piece 17 so that the cross bow extends parallel -to the ground surface and projects equall to ed below the guide rails 7 so'as to b-e `below the glider runway and not interfere with the glider skid should the gliderfail to leave the runway prior to reaching the'forward end of the track. An elastic draft cable or shock cord 20 is attached as by suitable coupling means 21 to the ends vof the cross bowl and has suitably attached thereto at apoint inid-.

way itspoints a suitable shock cord ring 22. The shock cord 20 may be of any ksuitable strength in accordance with the desired launching power required and likewise the strength of the cross spring bow may vary in accordance with the required launching power.

The launching means Cfurther includesa towing Vblock 23 of shuttle-like formation for free sliding movement in the slide way or track groove 9. rl`his towing block as will be observed in Figure 3 is of elongated forma- '60,.;

tion and has a tapering forward end topermit free sliding movement of Vthe block. Projecting upwardly from the'central portion of the towing block is a guide extension 24 for sliding-movement in the guidefslotS,

and projecting above the extension 24 is a Coni preferably cylindrical towing blockpost 25 preferably having a tapered upper end. This post 25 as will be observed in Figures 2 and 3 projects above the horizontal portions of the guide rails 7 and forms a coupling post for receiving the shock cord ring 22.

The retracting or tensioning means D for the launching means C- preferably comprises a geared winch 26 detachably mounted at the rear end of the track A and embodying a winding drum 27 on. whichis intended to be wound a retracting cable 28. This retract'- ing cable'28' extends thru the slide way or track groove 9 and at its free end is provided with a suitablering 29 adapted for detachable connectionhwith a suitable hook or 'the like 2O projecting from the rear end of vthe towing block 23. The winch may be operated by the crank 31 for winding the cable'28 upon` the drum 27 and drawing lthe towing block rearwardly inthe track groove 9.

ln lacinO the launchinorv means in 'a launching condition, the retracting cable'ringl 29 may behooked over the hook 30 with the towing blockat a location adjacent the forwardA end: of the track and then the shock cord ring 22 placed over the towing block f post 25. The winch 26 may then be operated for winding the cable 28 upon the drum 27 and drawing thetowing block rearwardly in the track groove9 and applying a tension on the cross bow 16'and shock cord 2O.` The towing block 23- is retracted -to a position where it is automatically retained by the re l-ease'ineans E carried bythe track section 32. i'

This release means E 'for releasably retain# ing the towing block in itsretrac'ted position may embody a rock shaft33 mounted trans veisely beneath the track section A32" and' carrying a trigger arin 34 provided with aj Pawj of Sear 35 which projects upwardly thru an opening inthe bottoni channel wall 5 for engaging in aV suitablev notch 6 provided in the under side of thetowing block 23.` Act`- ing between thelower endl of the trigger aim 34 and the under side wall 'is an expansion coil spring 37 acting to normally urge the the end of the cross arm and be trained tli'ru suitable guides 40. From the guide`sf40- the pull ropes extend rearwardly toward the? winch 26 andhave attached 'to their endsl suitable handles 41 to be gripped by a personV seated in the glider to be launchech If so' desired merelypne of the pull ropes'niay be provided and it'willy be seen that when'a pull is exerted on the pullropes that the trigger arm will'be swung upwardly compressing the spring 37 and retracting the sear 35 froin'thenotch 36Iand releasing the towing block. It

may here be well to mention thatthelretract-d ing cable ring 29 is preferably released 'rom the hook 30 before releasing the towing block.

Various means may he provided for rcleasably coupling the glider to the towing block and in the erample shown, a short coupling cable is provided, one end of which may be connected in any suitable manner to the nose ofthe glider and the opposite end oi which is provided with a coupling ring i3 adapted to be :slipped over the towing block post 25 above the shock cord ring 22. Thus when the lowing block 23 is released, the glider will be drawn forwardly over the track by the launching means C.

A novel drag means provided 'for relieving the snap or jerk during in it'al n'ioveincnt of the towing block and allow 1 a smooth release and quick pick-up for the glider and this means is provided in the track section 32 and produces a wcdging action upon the towing block when in its retracted position. This drag means preferably `consists of a hard wood strip -ll fined longitudinally upon the inner surface of one of the channel side walls t5 and extended substantially tliruout the length of the track section. Carried by the opposite side wall (i is a wedge-shaped wooiilcn strip lli which is normally urg l toward the fixed drag strip lo by means of a suit number of expansion coil sprin'rs f may have the tension thereof varied by ad- ;Austable stud holte 4S. The wedge-shaped drag strip i-6 as will he observed in Figure il tapers tmvard the forward end of the track section and tapering allows for gradual increase in speed pick-up as the towing block is moved between the drag strips V.l ve wedging action of the strips ipon the sides of the towing block at the forward end ofthe strips will be relatively slight and owing to the taper of the strip d6, a smooth and quick pick-up will he hac as the towing block moves forwardly. Three it will lie that when the towing block is released that the dra ging action created by the strips /l and 4:6 willrclieve the snap or jerk which would otherwise be inherent and allo\.vs for a smooth yet substantially quick pick-up during initial movement of the towing block.

An arrangement is provided for insuring positive release of the rings 22 and from the towing block post 25 and this means is preferably incorporated in one of the torward track sections and as shown in the track y This receiving trough 52 may be secured in any preferred manner to the under side of the track section and as the towing block is forced downwardly thereinto by the beveled detlecting strips the towing `block post 25 will be drawn thru the guide slot 8 and the rings 22 and 43 vforced off of the post. The forward end` of the trough 52 may be provided with a suitable shock absorbing means 1 ln use, theshockcord ring 22 is placed over the post 25 and the retracting cable ring 29 engaged over the towing block hook 30. The winch 26 is then operated for winding the cable 28 upon the drum 27 and drawing the towing block rearwardly in the track groove until the scar 35 automatically engages in the recess 36 and reta-ins the towing block in its'retracted position. This rearward movementof the towing block fleXes the cross bow 15 and also tensions the elasticcable or shock cord 20. The retracting cable ring 29 `is then preferably uncoupled from the hook il() and the device is now in a launching condition. rlhe glider B is then placed upon the launching track rearwardly of the towing block and the ring i3 of the glider cable l2 placed over the post 25. The operator or pilot from a seated position in the glider ll then grasps one or both of the handles fl-l of the pull ropes 39 and exerts a `pull thereon which raises the trigger arm 3ft against the tension of the spring 37 and retracts the scar 35 tor freeing` the towing block 23. As the towingl block is released the tensioned bow 16 and shock cord 2O eXert a forward pull upon the towing block and the block is prevented from starting with a quick snap or jerk by the wedging action of the drag strips lo and i6 which permit of a smooth release but quick pick-up of the block. is the block is drawn forwardly in the launching track the glider is moved with it and in most cases will be raised from the track and freed from the towing` block post before the block reaches the deliecting track section 32.

is the towing block reaches the track section 32 the force of the cross bow 16 and shock cord 2() will be spent and the towing block will be deflected into the receiving trough 52 by the deliecting strips 50. This downward movement of the towingI block serves to positively release the rings 22 and 413 from' the towing block post and prevents any possible hanging of the glider coupling cable to the block.

From the foregoing description it will be apparent that a `novel device for the launching of gliders7 sail planes, model planes or other motorless aircraft has been provided whereby the aircraft will be projected with considerable propelling force and without a snap or jerk occurring during initial movenient of the aircraft from the launching device. It will also be apparent that a novel arrangement has been disclosed whereby a single person may operate the device and lll@ launch a glider while seated therein. Itv will further beapparent that a novel arrangement has been shown permitting-ready-,and easy transporting of the device `due to its knockdown construction.

Changes in detail may bemade to the form of invention herein shown and described, without departing from' the spirit of the invention or the scope of the following claims.

I claim:

l. In a launching device for aircraft,.the combination of a track,.la unching means including a towing memberslidablyv guided in kthe-track and means for propelling the towing member forwardly in the track, retracting mea-ns for the towing member for tensioning the propelling means, releasable keeper means for retaining the towing member in a retracted position, and drag means for retarding initial movement of the towing member when released. Y

2. In a. launching device for aircraft, the combination of a track, a towing member slidably guided in thetrack, an elastic cab-le connected at the forward end of the track and-having connection with the towing member, retractingmeans for the towing member for tensioning the elastic cable, `releasable keeper means for retaining the towing member in a retracted position, and drag means frictionally engageable withthe towing member for retarding initial movement thereof when released.

3. In a-glider launching device, the combination of a track, atowing-block slidably guided in the track, a shock cord connected at the forward end of the track and having releasable connectionv with the towing block, means for drawing the towing block rearwardly in the track for placing the shock cord under tension, releasable vkeeper means for retaining the towing block in a retracted position, friction drag means-for retarding initial movement of the towing block, and means for releasing the shock cord from the towing block adjacent the forward end of the track.

Il. In a glider launching device, the combination of a track, a towing block slidably guided in the track, a shock cord conne-cted at `the forward end of the track and having releasable connection Vwith the towing block, means for drawing the towing block rearwardly in the track for placing the shock cord under tension, releasablekeeper means I for retaining Vthe towing block in a retracted position, lfriction drag means for retarding initial movement of the towing block, a coupling cable for the glider and having detachable coupling with the towing block, and

" means for releasing the coupling cable from the towing block adjacent-theforward end of the track. Y

5. In a launching device for gliders, the combination of a track, a towing block slidably guided in the track, anelastic cable connected between the forward end of the track and the block, a retracting cable connectedA to the block and extending rearwardly therefrom to thetrack, a rotatable drum mounted at the rearend of the track upon Whichfthe retracting cable is wound for retracting the towing block and tensioning the elastic cable,

releasable keeper means for retaining `they the towing block, retracting means mounted 'at the rear end of the track for drawing the towing block rearwardly in the track and placing a tensionV upon the cross bow and shock cord, releasable .keeper means `for retaining the towing block in a retracted position, and-means for detachably coupling the glider to the towing block.

7. In a launching device for gliders,the combination of a track, a towing block slidably guided in the track, a cross bow mounted at the forward ends of the track, a shock cord connected at the end of the cross bow and having connection at the central portion to the towing block, retracting means mounted at the rear end of the track for drawing the towing block rearwardly in the track and placing a tension upon the cross bow and shock cord, releasable keeper means vfor retaining the towing block in a retracted'position, means for retarding initial movement of the towing block when released, a glider coupling cable releasably coupled to the towing block, and means for releasin the glider coupling cable from the towing lock adjacent the forward end of the track.

8. In a launching device for gliders, the

combination of a track, a towing block slid-v means for retarding initial movement of the towing block when released, and deiiecting means for the towing block at .the forward end of'theftrack for releasing the glider coupling ring from thetowing block.

9. In a launching device for gliders, the combination of a. track,.a towing block slidablyV guided in the track and provided with an upstanding coupling post, a cross bow mounted at the forward end of the track, a shock cord connected to the ends of the cross bow and provided midway its ends with a coupling ring for positioning over the towing bloeir post, means for retractng the towing block in the track, releasable keeper means for 'staining the towing block in a retracted position, a glider coupling cable having a coupling ring for positioning over the towing block post, and dcileeting means arranged in the path of movement of the towing block adjacent the forward end of the track for freeing the shock cord and i:glider coupling cables from the coupling post of the towing block.

l0. ln a launching device for gliders, the combination of a track having a slide way and a slot opening along the upper side of the slide way, a towing block guided in the slide way and having an opstanding coupling post projecting thru said slot, propelling` means for the towing block including a shock cord having its ends connected to the forward end of the track and a coupling ring intermediate its end for positioning over said coupling post, means for moving the towing block rearwardly in the track for tensioning the shock cord, manually releasable keeper means for retaining the towing block in a retracted position, a glider coupling cable provided with a coupling' ring for positioning over the upstanding coupling post of the towin g block, a receiving trough opening into the lower side of said slide way adjacent the forward end of the track, and deflecting strips arranged in the slide way at opposite sides of the slot for directing the towing block downwardly into the receiving trough and causing movement of the shock cord and glider coupling cable rings olf of the towing block post.

ll. In a launching device for gliders, the combination of a track including a channelshaped lower portion embodying side wells, launching means including a towing block slidaoly guided in the track between said side walls and shock cord means for propelling the towingblock forwardly in the track, retreating means for the towing block, releasable keeper means for retaining the towing block in a retracted position, and drag means for retarding initial movement of the towing block embodying dii'ag strips farried by said track side walls in frictional engagement with opposite sides of the towing block when in its retracted position.

ln a launching device for gliders, the combination of a track including a channelshaped lower portion embodying side walls, launching means including a towing block slidably guided in the track between said side Talls and shock cord means for propelling the towing block forwardly in the track, retracting means for the towing block, releaslaunching means including a towing block slidably guided in the track between said side walls and shock cord means for propelling the towing block forwardly in the track, retracting means for the towing block, releasable keeper means for retaining the towing block in a retracted position, drag means for retarding initial movement of the towing block including fixed and yieldable drag strips carried by said track side walls for frictional engagement with the sides of the towing block when in its retracted position, one of said strips being of tapered formation and tapering toward the forward end of the track and means for varying the dragging action of the tapering strip upon the towing block.

14. In a launching device for gliders, the combination of a track, a towing block slidably guided in the track, a shock cord connected between the forward end of the track and block, means for releasably retaining the towing block in a retracted position, and means for retarding initial movement of the towing block including friction strips engageable with the towing block when in aretracted position, one of said strips being spring urged toward the towing block and being tapered in the direction of movement of the block when released.

15. In a launching device for gliders, the combination of a track, a towing block slidably guided in the track, a shock cord for propelling the towing block forwardly in the track, and releasable keeper means for retaining the towing block in a retracted position embodying a sear releasably engaging the towing block, a spring urged trigger arm normally retaining the sear in holding engagement with the block, and pull cables connected with the trigger arm and extending rearwardly therefrom to be grasped by an operator seated in a glider positioned upon the track rearwardly of the retracted position of the towing block.

16. In a launching device for gliders, the combination of a track embodying separate sections, means connecting the sections in longitudinal alignment, means bracing the connected sections, a sectional spring cross bow connected at the forward end of the track, a shock cord connected with the ends of ico the cross bow, a towing, memberrslidably guided in the' track,.mezms connecting the shock` cord to-the towing member, a Winch mounted at the rear end of. the trackand including a drum, a. retractnglcable connested with the towing. member and adapted tovbfywomnd4 on said drum, and releasable keeper.- means for retainngfthe towing memher nga;retracted.launching position.

VIRGIL A. SIEVENS.` 

